A conventional optical element package is configured to include a housing and a lid thereof, which lid has an aperture through which light from outside the optical element package is incident upon an optical element in the housing. In order to hermetically seal the optical element, a light-transmitting glass member is provided so as to cover the aperture.
Patent Literature 1 discloses an optical switch module (optical element package) including a MEMS (Micro Electro Mechanical System) mirror array, as an optical element, in a housing. The optical element package includes a lid frame on an upper portion of the housing, and a glass member (sapphire in a plate-like form) is fixed to the lid frame via a fixing member. The lid frame has a rectangular aperture in its center, which aperture is covered by the glass member.
Patent Literature 2 discloses an optical element package (optical element containment package) including a wavelength tunable interference filter, as an optical element, in a housing. The optical element package includes a lid on an upper portion of the housing, and a first window member is bonded to an outside of the lid, while a second window member is bonded to an inside of the lid. The lid has a circular aperture in its center, which aperture is covered by the first window member and the second window member.
Patent Literature 3 discloses an optical element package including a wavelength tunable interference filter, as an optical element, in a housing. The optical element package includes a lid on an upper portion of the housing, and a glass member is fixed to the lid via a fixing member. The lid has a circular aperture in its center, which aperture is covered by the glass member.